1. Field of the Invention
This invention relates to vehicle suspensions and, in particular, to structures for trailing and forward arms commonly found in such suspensions.
2. Disclosure of Related Art
In a conventional vehicle suspension system, a suspension control arm has a first end rigidly connected to an axle of the vehicle and a second end pivotally connected to a bracket descending from the vehicle frame. The control arm may be coupled to the axle using conventional mounting hardware such as a U-bolt and mounting bracket. Alternatively, the mounting hardware may be eliminated by fabricating a control arm having first and second sidewalls through which the axle passes. The control arm slides onto the axle and is then welded in place. The control arms found in conventional suspensions may also include mounting brackets disposed thereon for springs, shock absorbers, and other components of the suspension.
The suspension control arms found in conventional suspension systems have several disadvantages. In particular, the control arm is often located parallel to the longitudinal axis of the vehicle (and perpendicular to the axis of the vehicle axle) at an outboard position. The springs found in conventional suspension systems, however, require sufficient clearance from the vehicle wheels and brake assembly components. Accordingly, brackets mounted to the control arm to support the spring extend in an inboard direction from the control arm and the spring load is not centered on the control arm. In the case of the above-described fabricated control arm, one attempt to overcome this problem has been to angle one of the two sidewalls of the control arm in an inboard direction and lengthen a lateral wall joining the two sidewalls. This configuration, however, requires a relatively large amount of material for the lateral wall and adds significant weight to the vehicle. Conventional control arms also often do not provide sufficient structural support and positional accuracy for mounting shock absorbers. Control arms that are configured to slide onto the axle have several additional disadvantages. In particular, a weld coupling the two sidewalls to the axle must be interrupted at several points thereby resulting in a relatively weak joint at a location that is subject to a relatively high level of stress. Further, because the control arm must be slid onto the axle, installation of other components of the suspension, brake, and wheel assemblies cannot be accomplished prior to installation of the control arm.
There is thus a need for a vehicle suspension and a control arm therefor that will minimize or eliminate one or more of the above-mentioned deficiencies.
The present invention provides a vehicle suspension and a suspension control arm therefor.
In accordance with one aspect of the present invention, a suspension is provided that includes a control arm extending between an axle and a bracket of a vehicle frame. The control arm may include a first member having first and second spaced sidewalls. Each of the first and second sidewalls may be angled in an inboard direction relative to an axis of the axle whereby the first and second sidewalls are further inboard proximate the axle than the vehicle frame bracket. Because both sidewalls are angled in an inboard direction, springs loads can be centrally located on the arm without the material costs and increase in weight found in conventional systems.
In accordance with another aspect of the present invention, the suspension control arm may include a second member that is coupled to the first member. The first member may define a first recess at one end that corresponds to a first portion of an outer surface of the axle. The second member may define a second recess corresponding to a second portion of the outer surface of the axle. The second member is coupled to the first member after the axle is received within the first recess. In this manner, the control arm is capable of surrounding much, or even all, of the axle without the need to slide the control arm onto the axle. As a result, other suspension, wheel and brake assembly components can be installed prior to installation of the control arm. Each of the first and second members of the control arm may include a pair of spaced sidewalls and a lateral wall joining, and integral with, the two sidewalls. In accordance with another aspect of the present invention, the edges of the two sidewalls and the lateral wall abut the outer surface of the axle forming a continuous weld path for a weld that couples the control arm to the axle. As a result, the weld produces a relatively strong joint at a location that is subject to a relatively high level of stress. Finally, in accordance with another aspect of the present invention, the control arm may include a tube extending through the sidewalls and configured to receive a fastener. The eye of a shock absorber may be disposed about the fastener. The resulting configuration provides a stronger and more accurate mounting point for the shock absorber as compared to conventional control arms with welded mounting brackets.
These and other features and objects of this invention will become apparent to one skilled in the art from the following detailed description and the accompanying drawings illustrating features of this invention by way of example.